From the Independent's most cited article: Snowfalls are now just a thing of the past by Charles Onians:

However, the warming is so far manifesting itself more in winters which are less cold than in much hotter summers. According to Dr David Viner, a senior research scientist at the climatic research unit (CRU) of the University of East Anglia, within a few years winter snowfall will become "a very rare and exciting event".

"Children just aren't going to know what snow is," he said.

It seems despite the sage advice from that East Anglia CRU scientist, a new record for snowfall has been set for the month of December.

From the Rutgers University Snow Lab, we have the above graph for the Northern Hemisphere for all months of December. December 2012 was a clear winner.